/*
 * Copyright 2021 ZhongChao Blockchain Technology Research Institute.
 *
 * Copyright ConsenSys AG.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * This file has been modified by ZhongChao Blockchain Technology Research Institute to add support for Brochain.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package link.luyu.plugin.brochain.trie;

import org.apache.tuweni.bytes.Bytes;

public class CommitVisitor<V> implements LocationNodeVisitor<V> {

    private final NodeUpdater nodeUpdater;

    public CommitVisitor(final NodeUpdater nodeUpdater) {
        this.nodeUpdater = nodeUpdater;
    }

    @Override
    public void visit(final Bytes location, final ExtensionNode<V> extensionNode) {
        if (!extensionNode.isDirty()) {
            return;
        }

        final Node<V> child = extensionNode.getChild();
        if (child.isDirty()) {
            child.accept(Bytes.concatenate(location, extensionNode.getPath()), this);
        }

        maybeStoreNode(location, extensionNode);
    }

    @Override
    public void visit(final Bytes location, final BranchNode<V> branchNode) {
        if (!branchNode.isDirty()) {
            return;
        }

        for (byte i = 0; i < BranchNode.RADIX; ++i) {
            final Node<V> child = branchNode.child(i);
            if (child.isDirty()) {
                child.accept(Bytes.concatenate(location, Bytes.of(i)), this);
            }
        }

        maybeStoreNode(location, branchNode);
    }

    @Override
    public void visit(final Bytes location, final LeafNode<V> leafNode) {
        if (!leafNode.isDirty()) {
            return;
        }

        maybeStoreNode(location, leafNode);
    }

    @Override
    public void visit(final Bytes location, final NullNode<V> nullNode) {}

    private void maybeStoreNode(final Bytes location, final Node<V> node) {
        final Bytes nodeRLP = node.getRlp();
        if (nodeRLP.size() >= 32) {
            this.nodeUpdater.store(location, node.getHash(), nodeRLP);
        }
    }
}
